Liberal eugenics according to one version is distinguished from authoritarian eugenics on the basis that the choice of enhancement is devolved to parents. The argument for liberal eugenics combines a commitment to the right of parents to autonomy – in reproductive decisions and in the upbringing of children – and a parity claim that there is no morally significant difference between ante-natal and post-natal alterations of a child. The article reviews the putative constraints on parental choice, and assesses some criticisms of the parity claim. It concludes that a liberal commitment to social justice is in tension with a liberal commitment to parental choice, but judges that the former commitment does not entail the authoritarian eugenics which is represented as the alternative to liberal eugenics.